A number of prior art devices exist which relate to the construction of a staircase, or the repair or refurbishing of a staircase. Particularly for conventional outside stairs and emergency stairs in both residential and commercial applications, such stairs are often constructed of materials which do not withstand heavy traffic or harsh environmental conditions. Because of safety concerns, stairs should always be kept in a high state of maintenance. However, the cost to repair damaged staircases can be quite prohibitive, even for minor flaws. For example, stairs formed of concrete which have chips or other surface defects are not only dangerous, but are also unsightly. Concrete repair is usually a very temporary measure and, particularly in high traffic areas, the concrete repair is never as wear-resistant as the original concrete. For wooden stairs, the wood has a tendency to warp or deform along heavy traffic areas. Even if constructed of treated lumber, the wood becomes unsightly over time.
There are a number of examples of prior art devices which have attempted to overcome one or more of the following problems. These devices can be in the form of either a repair unit, or a complete staircase construction.
U.S. Pat. No. 5,357,724 discloses a stair tread in which rubber sheet material is placed around a metal core section, and then heated to melt the sheets together. Once heated, the core section is encapsulated within the rubber. The stair tread has anti-slip serrations formed on its upper surface. A front face or overhanging front lip forms the front edge of the stair tread, and a vertically extending rear flange forms the rear face or edge of the stair tread. The upper edge of the rear face has a groove to accept the lower edge of a riser board, while the upper edge of the riser board is inserted into a corresponding groove formed in the lower edge of the front face of the next higher stair tread.
U.S. Pat. No. 5,799,448 discloses an adjustable closed riser metal staircase system. The system includes a plurality of stair treads which may be assembled into staircases having different rise heights. The stair treads include a vertical riser portion and a horizontal walking surface, preferably made of a slip-resistant material such as Mebac.TM., a coating of thermally sprayed steel encapsulating a dispersion of grit materials, normally aluminum oxide. The nose piece portion of the stair tread is formed at the front of the stair by bending the forward edge of the steel plate downward. When assembled, the upper end of the riser portion is inserted within a channel created by the bent nosepiece of the next higher stair tread assembly.
U.S. Pat. No. 4,783,939 discloses a composite covering for improving worn-out treadways of steps. This covering includes a stair tread section which is placed over the existing stair tread, and an integral vertical flange which overhangs the front lip of the stair tread section. The covering is constructed of a scuff-resistant plastic. The underside of the stair tread section includes an insert of pressboard, and a binder which helps raise the elevation of worn out sections or indentations, and also serves to bind the layers of the composite covering.
U.S. Pat. No. 5,660,009 discloses a metal stairway construction in which stair steps are supported between a pair of trimmed sheet metal stringer panels on each side of the stairway. Each step of the stairway is formed of metal treads and risers cut to appropriate lengths from conventional joice members provided on site. The metal treads and risers are attached at opposite ends thereof to respective stringer panels by way of standard angle brackets. Threaded self-drilling fasteners attach each angle bracket to a corresponding stringer panel and to an associated metal tread or metal riser. Wooden treads and risers are attached over the corresponding metal treads and risers by standard self-drilling screws.
While the foregoing references may be adequate for their intended purposes, there are certain advantages with the present invention which are not found in these references. One advantage is that the staircase repair device of this invention can be used with any type of existing staircase, whether it be concrete, wood, or metal. Another advantage is that this staircase repair device can be used to repair a staircase without preparation or modification of the original staircase wear surfaces. Yet another advantage not overcome by the prior art is the use of a staircase repair device which has high strength and weathering capabilities, yet does not detract from the general aesthetic appearance of the staircase. The same advantages discussed above also apply to the staircase of this invention. Additionally, the staircase of this invention is simple in design, and can be used for stairways in a wide array of residential and commercial buildings.